In adjusting imaging parameters of an ultrasound imaging system, a user often makes compromises among the interrelated image characteristics of spatial resolution, temporal resolution, and sensitivity. As is well known in the art, "spatial resolution" and "temporal resolution" respectively refer to the ability to detect or separate closely spaced objects in space and the ability to detect temporal variation. As is also well known in the art, "sensitivity" refers to the ability to perceive imaged structures associated with weak return echo amplitudes. For example, in a B-Mode image, spatial resolution is determined by many imaging parameters such as operating frequency, number of transmit foci, spatial filter, and temporal filter. Most of these imaging parameters also either directly or indirectly affect temporal resolution and sensitivity. Most users, however, do not understand the physics of ultrasound or signal processing enough to appreciate the various ways these imaging parameters interplay with each other and, as a result, do not optimally adjust the imaging parameters.
Application-specific system presets offer a typically unsatisfactory solution to system optimization. In many ultrasound imaging systems, a user can select an application-specific system preset corresponding to the part of the body he is imaging (e.g., abdomen, carotid, small parts). Application-specific system presets are typically designed conservatively to provide good image quality for a wide range of patient population and for most imaging situations. However, for a particular application, the specific imaging parameter configurations that will result in optimal spatial resolution, temporal resolution, and sensitivity can vary from study to study or from user to use. As a result, the user is again presented with the problem of adjusting individual parameters without understanding how the individual imaging-parameter controls work and the inter-relationships and compromises associated with each parameter. The problem is aggravated when several components, each with their own system-specific features, are used.
In addition to application-specific system presets, some ultrasound imaging systems offer limited control over the relative priority of imaging parameters that affect both spatial and temporal resolution but not sensitivity. Separate controls for imaging parameters that affect sensitivity are typically needed because of the complexity involved in coordinating the parameters that affect sensitivity with the parameters that affect spatial and temporal resolution. For example, the Space/Time control on the Sequoia.TM. imaging system by Acuson Corporation controls some beamformer parameters such as the transmit and receive aperture size, number of beams acquired in parallel, and line density. With other systems, a corresponding feature may only control line density. Because they do not affect sensitivity, these limited controls do not provide optimal performance.
There is, therefore, a need for an ultrasound imaging system user interface that will overcome the problems described above.